Personally, I got my blazer at a thrift store; but you would have to be pretty lucky to find two of the exact same ones at a thrift store so that looks like it's a no-go. Making one yourselves(OR commissioning them) would ensure that you get the kind of fabric you want, and that they are identical.
If you don't want something made to order, I think blazers are pretty "in" right now, so maybe you could run in to some at typical trendy stores? Or you could check online somewhere like Amazon that has a really big selection, and you can search by color.